# class MyList():
#     def __init__(self,list=[]):
#         self.list = [x for x in list]
#     # 当直接打印实例（如print(Mylist)）时，会调用 __repr__
#     def __repr__(self):#返回一个字符串
#         return "MyList %s" % self.list
#     def __add__(self,other):
#         #此处的 + 表拼接
#         # self.lis接收list1 other.list接收list2
#         return self.list + other.list
#     def __mul__(self,rhs):
#         return self.list * rhs
#     def __rmul__(self,lhs):
#         return self.list * lhs
#     def __iadd__(self,other):
#         self.list += other.list#没有返回值，self.list会自增
#         return self.list
#     def __add__(self,other):
#         return self.list & other.list
#     def __or__(self,other):
#         return self.list | other.list
#     def __xor__(self,other):
#         return self.list ^ other.list
#
#     #返回当前维护的list的每一个数值的相反数
#     def __neg__(self):
#         # L = [-x for x in self.list]
#         L = (-x for x in self.list)#生成器推导式
#         return MyList(L)
#
#     def __contains__(self,item):
#         # while True:
#         #     if item in self.list:
#         #         return True
#         #     else:
#         #         return False
#         for i in self.list:
#             if i == item:
#                 return True
#         return False
#
#     def __getitem__(self,i):
#         return self.list[i]
#     def __setitem__(self,i,value):
#         self.list[i] = value
#         return self.list[i]
#     def __delitem__(self,i):
#         del self.list[i]
#         return self.list[i]
#
#
# L1 = MyList([1,2,3,4,5])
# L2 = MyList([1,2,3,4,5])
# # L1 += L2
# # print(L1)
# # print(5 in L2)
# # print(L1[0:3])
# L2[0] = 7
# print(L2)
# del L2[0]
# print(L2)

# class OrderSet:
#     def __init__(self,it):
#         self.data = []
#         for i in it:
#             if i not in self.data:
#                 self.data.append(i)
#
#     def __repr__(self):
#         return "OrderSet %s" % self.data
#
#     def __iter__(self):
#         return iter(self.data)
#
#     def __add__(self,other):
#         return OrderSet(self.data + other.data)
#
#     def __and__(self,other):
#         # item = []
#         # for x in self.data:
#         #     for y in other.data:
#         #         if x == y:
#         #             item.append(x)
#         # return OrderSet(item)
#         return OrderSet(
#             (x for x in self.data if x in other.data)#生成器推导式，相对于列表推导式更节省内存
#              )
#
#     def __or__(self,other):
#         # item = self.data.copy()
#         # for x in other.data:
#         #     if x not in item:
#         #         item.append(x)
#         # return OrderSet(item)
#         return OrderSet(
#             (self.data + other.data)
#         )
#
#     def __sub__(self, other):
#         return OrderSet(
#             (x for x in self.data if x not in other.data)
#         )
#
#     def __xor__(self,other):
#         # item = []
#         # for x in self.data:
#         #     if x not in other.data:
#         #         item.append(x)
#         # for y in other.data:
#         #     if y not in self.data:
#         #         item.append(y)
#         # return OrderSet(item)
#
#     #        生成器表达式本身并不是列表或元组，它们不能直接相加
#         # return OrderSet(
#         #     ((x for x in self.data if x not in other.data) + (y for y in other.data if y not in self.data))
#         # )
#
#         return OrderSet(
#             (self - other) | (other - self)
#         )
#
#     def __eq__(self,other):
#         return self.data == other.data
#
#     def __contains__(self,item):
#         return item in self.data
#
#
# set1 = OrderSet([1,2,5,8,7,8,5,1223,1234,7898])
# set2 = OrderSet([6,3,1,8,7,5,0,5])
# print(set1 & set2)
# print(set1 | set2)
# print(set2 - set1)
# print(set1 ^ set2)
# print(set1 == set2)
# print(9999 in set1)





# def myfun(obj):
#     #遍历obj的所有元素，得到每一个元素，再去遍历这个元素，查看是否含有空格
#     flag = False
#     for item in obj:
#         for i in item:
#             if i == " ":
#                 flag = True
#     return flag
#
# ["a    b","    asd", "df df d"]
with open('test.txt', 'w', encoding='utf-8')as file:
    L = file.readlines()
if len(L)>=3:
    del L[2]
with open('test.txt', 'w', encoding='utf-8') as file:
    file.writelines(L)